He represented the 34th district, which at the time included portions of Alameda County.
[2][3] John Leonard Rose was born on March 25, 1882[4] in Newark precinct[5] of Washington Township, Alameda County, California (present-day Newark, California[6]).
[4][5] Rose attended the University of California at Berkeley and graduated law school at Boalt Hall in 1907.
[6][7] During his early career, he had been a deputy district attorney for Alameda County and had been a law partner of Adolphus Frederic St. Sure.
He returned to private law practice as an inheritance tax appraiser for Alameda County, from 1927 until his retirement in 1947.